The present invention relates generally to construction components, particularly modular fencing components constructed of molded plastic material. More specifically, the invention relates to capping and connecting arrangements for tubular fence pickets, posts and rails, and conduit, as well as other structures.
Modular fencing components are known, e.g., in the agricultural and residential industries. For such fencing components, plastics present a beneficial alternative to other materials such as wood. Plastics can be made to take on the desirable external appearance of wood, while exhibiting superior durability and resistance to the elements. In addition, plastic fencing components can be easier and faster to assemble, and they require less maintenance than wood components. Plastic components can also be recycled, and they are less expensive to produce than comparable wood components.
The use of plastics for fencing components is disclosed in Williams U.S. Pat. No. 5,755,431 and West et al. U.S. Pat. No. 5,853,167. In these constructions, open-ended tubular posts are covered by plastic caps that protect and provide a more aesthetically pleasing appearance to the ends of the posts. West et al. disclose such a decorative cover made from a collar that covers the end of a post and an ornamental cap that snaps into the collar.
Caps also have been secured to their corresponding posts by adhesive or mechanical fastening means, such as nails, screws, or rivets. These methods of attachment have several disadvantages. First, they are labor-intensive. In addition, they require the installer to take significant care and effort in their installation. For example, the plastic in the components can be stripped or broken away by mechanical means, and adhesive spills can mar the aesthetic appearance of the fence. Furthermore, adhesives require good surface contact to be effective, and they can contain harsh chemicals that are harmful to the environment and to those applying the adhesives.
Simpson et al. U.S. Pat. No. 5,078,367 and Yoder U.S. Pat. No. 5,931,450 disclose caps that are attached to corresponding tubular posts by a friction fit. With these arrangements, manufacturing tolerances may lead to a friction fit that is too tight or too loose. If the fit is too tight, it may be difficult to install the cap on its corresponding post; if it is too loose, the cap could fall off or be removed inadvertently. Even if the cap fits its corresponding post well, repeated removal may lead to loosening of the cap due to wear, and the cap can still be removed by the elements or by vandals, leaving the end of the post exposed.
An arrangement that alleviates to a significant degree the above-mentioned problems is disclosed in Dodge et al. U.S. Pat. No. 5,421,556. Dodge et al. disclose post caps with a spring tab arrangement that snaps into a hole or groove in a corresponding post. These caps are easy to install and difficult to remove, but the posts must be prepared specially to accept the spring tabs by having holes drilled through their walls, or grooves cut in their inside surfaces.
Lawrence U.S. Pat. No. 5,645,270 discloses a cap that includes a resilient strip that extends between, and protrudes slightly from, opposite sides of an attachment portion of the cap. As the cap is inserted into a corresponding post, the protruded ends of the resilient strip scrape along the inside surfaces of the walls of the post. The curvature of the resilient strip acts as a spring, such that upon an attempt to remove the cap the ends of the strip dig into the inside surfaces of the post walls, making the cap difficult to remove. This design appears to avoid some of the problems of the prior art, but it includes both metal and plastic components that must be combined in a single cap, thus increasing manufacturing and assembly costs.
In view of the foregoing, it is a principal object of the present invention to provide an improved arrangement for securing a cap on the end of a tubular construction component, e.g., a fence picket, post or rail.
It is a more specific object of the present invention to provide a cap configuration that will provide a sure frictional attachment between the cap and tubular construction component despite potentially loose tolerances of the tubular construction component.
It is a further object of the present invention to provide a cap as aforesaid that may be molded as a single piece.
It is yet another object of the invention to provide a connector configuration that will provide a sure frictional attachment of one structure to another, despite potentially loose tolerances of the parts.
One or more of the above, and/or other, objects are achieved by the various aspects of the invention. In a first aspect, the invention provides a cap for a tubular construction component. The cap has a cover portion for at least partially covering an open end of the tubular construction component and an attachment portion having a line of flexure that allows one of the walls forming the attachment portion to partially collapse when the attachment portion is pressed into the open end of the tubular construction component. The partial collapse of the wall allows for a frictional engagement between the attachment portion and the tubular construction component.
In a second aspect, the present invention provides a kit for assembling a structural component assembly. The kit includes an elongated tubular construction component with an open end and a cap that is insertable into the construction component. The cap has a cover portion for at least partially covering the open end of the construction component and an attachment portion having a line of flexure that allows one of the walls forming the attachment portion to partially collapse when the attachment portion is pressed into the open end of the construction component. The partial collapse of the wall allows for a frictional engagement between the attachment portion and the construction component.
In a third aspect, the present invention provides a structural component assembly having an elongated tubular construction component with a cap inserted into one of its ends. The cap has a cover portion for at least partially covering the end into which it is inserted and an attachment portion having a line of flexure about which one of the walls forming the attachment portion is partially collapsed, creating a frictional engagement between the attachment portion and the construction component.
In a fourth aspect, the present invention resides in a connector for connecting one structure to another. The connector includes an attachment portion comprising a line of flexure which allows a first wall of the attachment portion to partially collapse when the attachment portion is pressed into an open end of a tubular structure, to thereby form a frictional engagement between the attachment portion and the tubular structure. In one embodiment of this fourth aspect, the connector comprises a pair of attachment portions situated at opposite ends of the connector.
The above and other objects, features, and advantages of the present invention will be readily apparent and fully understood from the following detailed description of preferred embodiments, taken in connection with the appended drawings.